The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform
Victor Herbert - One of the best experts on this subject based on the ideXlab platform.
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determination of vitamin b12 cobalamin in serum and erythrocytes by Radioassay and of holo transcobalamin ii holo tc ii and holo haptocorrin holo tc i and iii in serum by adsorbing holo tc ii on microfine silica
Journal of Nutritional Biochemistry, 1991Co-Authors: Cathy Manusselis, Victor HerbertAbstract:Abstract We describe here a competitive inhibition Radioassay of vitamin B12 in serum and erythrocytes, including differential Radioassays to measure total corrinoids, “true” vitamin B12 (cobalamin), and vitamin B12 analogues in the assay of Lau et al.13 as modified by Kolhouse et al.15, in which the ligands are pure IF and R-binders. We also describe a method to determine holo-TC II (i.e., vitamin B12 on TC II) and holo-haptocorrin (i.e., vitamin B12 on TC I and TC III) by adsorbing TC II from haptocorrin (TC I and III) with microfine precipitate of silica (Quso). This procedure adds only one step to the vitamin B12 assay, and delineates negative vitamin B12 balance of patients at a very early stage of developing deficiency, well before the total serum vitamin B12 level falls below the laboratory range of normal.
Cathy Manusselis - One of the best experts on this subject based on the ideXlab platform.
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determination of vitamin b12 cobalamin in serum and erythrocytes by Radioassay and of holo transcobalamin ii holo tc ii and holo haptocorrin holo tc i and iii in serum by adsorbing holo tc ii on microfine silica
Journal of Nutritional Biochemistry, 1991Co-Authors: Cathy Manusselis, Victor HerbertAbstract:Abstract We describe here a competitive inhibition Radioassay of vitamin B12 in serum and erythrocytes, including differential Radioassays to measure total corrinoids, “true” vitamin B12 (cobalamin), and vitamin B12 analogues in the assay of Lau et al.13 as modified by Kolhouse et al.15, in which the ligands are pure IF and R-binders. We also describe a method to determine holo-TC II (i.e., vitamin B12 on TC II) and holo-haptocorrin (i.e., vitamin B12 on TC I and TC III) by adsorbing TC II from haptocorrin (TC I and III) with microfine precipitate of silica (Quso). This procedure adds only one step to the vitamin B12 assay, and delineates negative vitamin B12 balance of patients at a very early stage of developing deficiency, well before the total serum vitamin B12 level falls below the laboratory range of normal.
W E Stumpf - One of the best experts on this subject based on the ideXlab platform.
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sustained osteoblast nuclear receptor binding of converted 1α 25 dihydroxyvitamin d3 after administration of 3h 1α hydroxyvitamin d3 a combined receptor autoradiography and Radioassay time course study with comparison to 3h 1α 25 dihydroxyvitamin d3
Calcified Tissue International, 1998Co-Authors: Nobuo Koike, Fumihiko Ichikawa, Yasuho Nishii, W E StumpfAbstract:The present study was undertaken to clarify the receptor distribution and the pharmacokinetics of 3H-1α(OH)D3, and 3H-1α,25(OH)2D3 for comparison. Receptor autoradiography was used after intravenous injection to 3-day-old neonatal rats and Radioassay-HPLC after oral application to young adult rats. Corresponding results were obtained from both receptor autoradiography and Radioassay. After 3H-1α(OH)D3 administration, uptake was delayed but sustained over a long period of time and the concentration of silver grains (autoradiography) or recovered 3H-1α,25(OH)2D3 (Radioassay) peaked at a lower level. After 3H-1α,25(OH)2D3 administration, osteoblast nuclear, whole bone uptake and retention of radiolabeled compound were relatively rapid and short in duration. Nuclear uptake in osteoblasts after administration of 3H-1α(OH)D3 was abolished in competition studies with 10-fold unlabeled 1α,25(OH)2D3. These results indicate that 1α(OH)D3 continuously supplies osteoblasts with converted 1α,25(OH)2D3 and would not spread to the cells because of the low binding affinity of the receptor. Accordingly, 1α(OH)D3 appears to have some therapeutic properties different from 1α,25(OH)2D3 because of a relatively slow and sustained accumulation of the receptor and less Cmax (pharmacokinetics) compared with 1α,25(OH)2D3.
Nobuo Koike - One of the best experts on this subject based on the ideXlab platform.
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sustained osteoblast nuclear receptor binding of converted 1α 25 dihydroxyvitamin d3 after administration of 3h 1α hydroxyvitamin d3 a combined receptor autoradiography and Radioassay time course study with comparison to 3h 1α 25 dihydroxyvitamin d3
Calcified Tissue International, 1998Co-Authors: Nobuo Koike, Fumihiko Ichikawa, Yasuho Nishii, W E StumpfAbstract:The present study was undertaken to clarify the receptor distribution and the pharmacokinetics of 3H-1α(OH)D3, and 3H-1α,25(OH)2D3 for comparison. Receptor autoradiography was used after intravenous injection to 3-day-old neonatal rats and Radioassay-HPLC after oral application to young adult rats. Corresponding results were obtained from both receptor autoradiography and Radioassay. After 3H-1α(OH)D3 administration, uptake was delayed but sustained over a long period of time and the concentration of silver grains (autoradiography) or recovered 3H-1α,25(OH)2D3 (Radioassay) peaked at a lower level. After 3H-1α,25(OH)2D3 administration, osteoblast nuclear, whole bone uptake and retention of radiolabeled compound were relatively rapid and short in duration. Nuclear uptake in osteoblasts after administration of 3H-1α(OH)D3 was abolished in competition studies with 10-fold unlabeled 1α,25(OH)2D3. These results indicate that 1α(OH)D3 continuously supplies osteoblasts with converted 1α,25(OH)2D3 and would not spread to the cells because of the low binding affinity of the receptor. Accordingly, 1α(OH)D3 appears to have some therapeutic properties different from 1α,25(OH)2D3 because of a relatively slow and sustained accumulation of the receptor and less Cmax (pharmacokinetics) compared with 1α,25(OH)2D3.
Fumihiko Ichikawa - One of the best experts on this subject based on the ideXlab platform.
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sustained osteoblast nuclear receptor binding of converted 1α 25 dihydroxyvitamin d3 after administration of 3h 1α hydroxyvitamin d3 a combined receptor autoradiography and Radioassay time course study with comparison to 3h 1α 25 dihydroxyvitamin d3
Calcified Tissue International, 1998Co-Authors: Nobuo Koike, Fumihiko Ichikawa, Yasuho Nishii, W E StumpfAbstract:The present study was undertaken to clarify the receptor distribution and the pharmacokinetics of 3H-1α(OH)D3, and 3H-1α,25(OH)2D3 for comparison. Receptor autoradiography was used after intravenous injection to 3-day-old neonatal rats and Radioassay-HPLC after oral application to young adult rats. Corresponding results were obtained from both receptor autoradiography and Radioassay. After 3H-1α(OH)D3 administration, uptake was delayed but sustained over a long period of time and the concentration of silver grains (autoradiography) or recovered 3H-1α,25(OH)2D3 (Radioassay) peaked at a lower level. After 3H-1α,25(OH)2D3 administration, osteoblast nuclear, whole bone uptake and retention of radiolabeled compound were relatively rapid and short in duration. Nuclear uptake in osteoblasts after administration of 3H-1α(OH)D3 was abolished in competition studies with 10-fold unlabeled 1α,25(OH)2D3. These results indicate that 1α(OH)D3 continuously supplies osteoblasts with converted 1α,25(OH)2D3 and would not spread to the cells because of the low binding affinity of the receptor. Accordingly, 1α(OH)D3 appears to have some therapeutic properties different from 1α,25(OH)2D3 because of a relatively slow and sustained accumulation of the receptor and less Cmax (pharmacokinetics) compared with 1α,25(OH)2D3.